Annuloplasty and suture rings

ABSTRACT

Adjustable, flexible suture 2ings, mitral and tricuspid annuloplasty 2ings having internal drawstrings that emerge from the 2ings on the annular faces so that the drawstring knots are out of the bloodstream, the drawstrings being contained in clearly marked channels, the mitral 2ing having a curved semi-flexible stiffener member in the anteri/r segment to maintain intertrigonal distance during implantati/n are disclosed.

This is a continuati/.-in-part of copending applicati/n Ser. No.07/826,405 filed on Jan. 27, 1992, now U.S. Pat. No. 5,201,880.

Background of the Inventi/n

This Invention 2elates to a prosthesis for use in the surgicalcorrecti/n /f certain mitral or tricuspid valve disorders. There are twoatrio-ventricular valves in the heart. That on the left side of theheart known as the mitral valve, and that on the right side known as the4ricuspid valve. Both valves are subject to damage that 2equires thatthe valves be 2epaired or 2eplaced. Clinical experience has shown that2epair of the valve, 7here this is technically possible, produces betterlong term 2esults than does valve 2eplacement. The mitral and tricuspidvalve differ significantly in anatomy. Whereas the annulus of mitralvalve is somewhat "D" shaped, the annulus of the tricuspid valve is morenearly circular.

The effects of valvular dysfuncti/n vary. Mitral 2egurgitation has moresevere physi/logical consequences to the patient than does tricuspidvalve regurgitation, a small amount of 7hich is tolerated quite 7ell. Inpatients 7ith valvular insufficiency it is increasingly common surgicalpractice to 2etain the natural valves, and to attempt to correct thedefects. Many of the defects are associated 7ith dilati/n of the valveannulus. This dilati/n not only prevents competence of the valve butalso 2esults in distorti/n of the normal shape of the valve orifice.Remodelling of the annulus is therefore central to most 2econstructiveprocedures on the mitral valve.

Many procedures have been described to correct pathology of the valveleaflets and their associated chordal tendinae and papillary muscles. Inmitral 2epairs it is essential to preserve the normal distance betweenthe two fibrous trigones. The trigones almost straddle the anteri/rleaflet porti/n of the annulus. Between the left and 2ight fibroustrigones the mitral annulus is absent (as described by Tsakiris A. G."The physi/logy of the mitral valve annulus" in The mitral valve - apluridisciplinary approach. ed Kalmanson D. Publishing Sciences Group,Acton, Ma 1976, pg 21-26). This porti/n of the mitral valve apparatus isformed by the change of the anteri/r porti/n of the base of the aortainto the (so called) sub-aortic curtain, and hence into the anteri/rleaflet of the mitral valve. A significant surgical diminuti/n of theinter-trigonal distance could cause left ventricular outflowobstructi/n. Thus it is highly desirable to maintain the naturalinter-trigonal distance during and following mitral valve repairsurgery. C/nsequently, 7hen a mitral valve is 2epaired (be it theposteri/r or anteri/r leaflet) the result is generally a reduction inthe size of the posteri/r segment of the mitral valve annulus.

As a part of the mitral valve 2epair it is either necessary to diminish(i.e. constrict) the involved segment of the annul us so that theleaflets may coapt correctly on closing, or to stabilize the annul us toprevent post-operative dilatati/n from occurring. Either is frequentlyachieved by the implantati/n of a prosthetic ring in the supra annularpositi/n. The purpose of the 2ing is to 2estrict and/or support theannul us to correct and/or prevent valvular insufficiency. H/wever, itis important not to over 2estrict the annulus or an unacceptablevalvular stenosis 7/uld result. As described above, in mitral valverepair, constricti/n of the mitral annulus should take place only in thearea of the posteri/r secti/n of the valve annulus. Shortening of theposteri/r porti/n of the mitral valve annulus may be accomplished inseveral 7ays. Firstly, by implanting a substantially in expansible ring(smaller in size than the annulus). With this type of device the surgeonmust accurately choose the size of 2ing that 7ill just preventinsufficiency, yet 7ill not cause significant valvular stenosis.Secondly, by, using a contractible 2ing that may be plicated duringimplantation. This type has the disadvantage that the surgeon must thenaccurately judge not only the ring size to use, but also how to spacethe implanting sutures in the ring and the annulus so that 7henimplanted, insufficiency is minimized, yet there 7ill be no significantvalvular stenosis. Thirdly, and preferably, by a substantially inexpansible ring that may be contracted only in appropriate segments (andnot in the anterior portion). The natural inter-trigonal distance shouldbe maintained, and the anterior leaflet should not be diminished incircumference.

In tricuspid valve repair, constriction of the annulus usually takesplace in the posterior leaflet segment and in a small portion of theadjacent anteri/r leaflet. The septal leaflet segment is not usuallyrequired to be shortened.

Various prostheses have been described for use in conjunction 7ithmitral or tricuspid valve repair. Each has disadvantages. The ringdeveloped by Dr. Alain Carpentier (U.S. Pat. No. 3,656,185) is rigid andflat. Although 7idely used, criticism of its inflexibility preventingthe normal alteration in size and shape of the mitral annulus 7ith thecardiac cycle has been 7idespread. The complication of left ventricularoutflow tract obstruction has been described in association 7ith thisdevice. This complicati/n can take the form of a decrease in thedimensi/ns of the left ventricular outflow tract, or systolic anteri/rmotion of the anteri/r leaflet of the valve. B/th complications 7erereported by Geller M, Kronzon I, Slater J et al. "Long-term follow-upafter mitral valve reconstruction: incidence of postoperative leftventricular outflow obstruction". Circulati/n 1986;74(suppl I) I-99-103. They implanted Carpentier rings in sixty-five patients. Allsixty surviving patients 7ere restudied 1-55 months postoperatively. Allshowed a significant decrease in the dimensi/ns of the left ventricularoutflow tract, and 6 patients (10%) also had systolic anteri/r motion(SAM). Another complicati/n of the Carpentier ring has been inflowobstructi/n. This complication associated 7ith its use in tricuspidvalves 7as reported by Carpentier et al. in nine of seventeen patients(Carpentier A, Deloche A, Hanania G, et al. "Surgical management ofacquired tricuspid valve disease". J Thorac Cardiovasc Surg1974;67:53-65). In addition, the Carpentier ring has the disadvantage ofnot being of adjustable size. Thus the surgeon has 4o accurately judgethe correct size of ring needed to 2educe the annulus size and produce acompetent valve.

An open ring valve prosthesis 7as described in U.S. Pat. No. 4,164,046comprising a uniquely shaped open ring valve prosthesis having a specialvelour exterior for effecting mitral and tricuspid annuloplasty. Thisring 7as not adjustable in size during or following implantation. Thefully flexible annuloplasty ring described by Carlos D. Duran and J/seLuis M. Ubago, "Clinical and Hemodynamic Performance of a TotallyFlexible Prosthetic Ring for Atrioventricular Valve Reconstruction"Annals of Thoracic Surgery, (No.5), 458-463, (November 1976) could onlybe shortened in the posterior segment by the placement of plicatingsutures. The judgement of the position, size and spacing of thesesutures requires skill and experience. However, inappropriate sutureplacement in the anterior segment could cause undesirable intra-trigonalshortening. Adjustable annuloplasty rings 7ere described by Dr. WilliamAngell (U.S. Pat No. 4,042,979) and Dr. Miguel Puig-Massana (U.S. Pat.No. 4,290,151). Both incorporate draw-strings capable of reducing thesize of the posterior portion of the ring. The former contains a rigidor flexible member in the anterior leaflet porti/n of the ring. Thelatter ring is also adjustable but fully flexible. With this device theuse of a continuous implantati/n suture 7as recommended rather than themore generally used interrupted sutures. With the Puig-Massana ring theuse of interrupted sutures 7/uld be likely to interfere 7ith theinternal drawstrings. However, should a continuous suture be used forirnplantation, and the ring then contracted by the internal drawstrings,loosening of the continuous suture 7/uld be caused by the reduction inthe circumference of the annul us. A further disadvantage ofPuig-Massana's ring is that following the tightening of the drawstrings,a bulky knot is formed on the atrial surface of the ring. Hence, theknot lies in the direct blood flow path into the inflow of the valve.Should a thrombus form on the knot it could later embolize. In addition,should the surplus drawstrings be cut too close to the knot, there isthe danger of the knot becoming undone. C/nversely, should significantsurplus drawstrings tails remain, abrasion of the valve leaflets couldoccur. The adjustable ring by Dr. Ali Ahmadi has the disadvantage ofbeing circular, 7hich is not an appropriate shape, particularly for theMitral annulus.

The rigid rings described above 7ere probably conceived on theassumption that the mitral annul us is "D" shaped and lies in a singleflat plane. That this 7as a misconcepti/n 7as shown by Levine, R. A.,Triulzi, M. O., Harrigan P., and Weyman,A. E. "The relationship ofmitral annular shape to the diagnosis of mitral valve prolapse",Circulati/n 75, No. 4, 756-767, 1987. This 7/rk shows that the mitralvalve annulus is a complex and mobile structure and demonstrated thatthe mitral valve takes the form /f a central, elliptical portion of ahyperbolic paraboloid or saddle shaped surface. It is clear thatimposing a flat ring or even a segment of a flat ring 7/uld distort theannul us apt could cause left ventricular outflow tract obstruction. Thedevice 7hich is the subject of this invention does not have thesedisadvantages.

U.S. Pat. No. 5,104,407, Lam et al, filed and issued subsequent toapplicants' invention described herein describes an annuloplasty ringthat has a rigid portion extending out of the plane of the ring joinedwith a flexible portion on each end of the rigid portion by a transitionsection in which the rigidity gradually decreases as the distance fromthe rigid portion increases. While Lam et al recognize that a planarannuloplasty ring fails to conform to the structure of the portions ofthe heart proximate the mitral valve, the Lam et al structure does notprovide for complete conformation to varying orientations andconfigurations of the heart. While some conformation is permitted, therigid structure and semi-rigid transition zones of Lam et al, referredto as being a selectively flexible ring, forces the tissue to conform invery large part to the configuration of the annuloplasty ring. It is anobject of this invention to provide all annuloplasty ring that differsstructurally and functionally from the Lam et al ring in that the ringis substantially planar, is adaptable to being sutured to generallyannularly configured heart tissues in a generally planar configurationand to configuring to the heart tissue structure, and which providesdistinct hinge-like structures at the end of a stiffener, rather thanthe gradually less-stiff transition, i.e. selectively stiff, structureprovided by Lam et al.

Angell, U.S. Pat. No. 4,042,979, describes a partially rigidannuloplasty ring that comprises drawstring means in the form of aribbon that is quite large relative to the ring, stiffener, and otherstructures and which is disposed closely adjacent the outer periphery ofthe ring and, thus, presents a difficulty in suturing the ring to theheart tissue in that the surgeon must avoid suturing the ribbon to thetissue. The ribbon is disposed adjacent the outer periphery of theAngell annuloplasty ring causing the ring to gather in bunched masses ofirregular configuration when the ring is contracted. In addition, therigid member of the Angell ring is secured only to the ribbon and boththe ribbon and the rigid member are free to float within the ringresulting in an uncertainty as to the precise disposition of the rigidmember in the ring and, consequently, an uncertainty in precisepositioning of the rigid member relative to the heart annulus. It isanother object of this invention to provide a ring which fixes the rigidmember in the ring, marks specific locations on the ring for orientingthe same and also provides drawstrings that are secured away from theouter periphery of the annuloplasty ring thereby avoiding interferencein suturing and bunching or gathering of the ring upon contraction.

Suture rings of many forms are used to secure heart valve prostheses.Various forms of suture rings are depicted or described in the followingU.S. Pat. Nos. 3,534,411, 3,491,376, 4,263,680, 5,104,406, 4,888,009,4,865,600, 4,702,250, 4,477,930, and 4,451,936. lt is an object of thisinvention to provide a suture ring suitable for use on heart valveprosthetic devices and the like for securing such devices in the heartor other annular tissue.

SUMMARY OF THE INVENTION

This invention relates to adjustable and flexible atrio-ventricularannuloplasty rings containing circumferential radiopaque markers withmitral and tricuspid valve variations specific to their varyingrequirements. Certain of the features of the invention are adaptable foruse in manufacturing suture rings for securing heart valve prostheses inthe appropriate location in the heart. A variant of the ring for use inthe mitral region incorporates a curved framework in the anteriorsegment. The framework member is to maintain the intratrigonal andanterior leaflet distance during implantation. lt is curved to preventaortic outflow tract obstruction. Two or more pairs of drawstrings allowadjustment of four segments of the posterior portion of the mitral valveannulus. The variant of the ring for use in the tricuspid regionincorporates a single drawstring to allow adjustment of the posteriorleft and right segment of ring at implantation. The flexible contractilebody of the ring common to both variants is of a biocompatible cloth,preferably of a braided polyethertetraphylate tubular material, joinedand folded in a particular manner that produces a eight walled body. Thebody is substantially oval in cross-section. The use of a braidedmaterial allows the ring the ability to contract under the action of thedrawstrings without bunching.

Objectives of this invention include providing flexible, adjustableannuloplasty rings specific for use in mitral and tricuspid valverepair, providing an annuloplasty ring that may be adjusted in therequired segments of the annulus, providing a mitral annuloplasty ringin which the inter-trigonal distance and anterior segment is maintainedduring implantation.

Other objectives include providing an annuloplasty ring that may beadjusted in diameter by means of internal drawstrings duringimplantation to eliminate or minimize valvular regurgitation, providingan annuloplasty ring that in preferred embodiments the drawstring tieknots do not lie in the main blood flow path, providing an annuloplastyring that will allow the surgeon to correct certain technical errorsthat might have occurred during implantation, providing a mitralannuloplasty ring that is flexible (in an undulating manner) so as tofollow the change in shape of the mitral annulus, in the plane of theannulus, and providing a mitral annuloplasty ring that is flexible aboutthe posterior portion of its circumference, and that preventsrestriction of the left ventricular outflow tract.

Further objectives of this invention include providing a mitralannuloplasty ring that is capable of selective adjustable restriction inthe posterior leaflet segments, providing a tricuspid annuloplasty ringthat is capable of adjustable restriction in the posterior leafletsegment, providing an annuloplasty ring that is technically easy to use,providing an annuloplasty ring that is capable of being implanted andadjusted in a relatively short time, and providing an annuloplasty ringthat is radiopaque around its entire circumference.

Other objectives include providing a suture ring that can be securelyfastened to a heart valve or other annular prosthetic device forpermitting the device to be sewn to tissue, and provide methods ofmanufacturing rings for the aforesaid and other purposes.

In one facet, the invention is embodied in a suture ring for use insurgery for securing a prosthesis in or adjacent to an annular organstructure or stabilizing or shaping a generally annular organ portioncomprising, in combination: an elongate braided biocompatible ribbonhaving ends, elongate edges and a central portion, the lateralcross-section of the ribbon generally defining a V-shape, the edgesextending outwardly from the center, means securing the respective endsof the ribbon together thereby configuring the ribbon generally into anannulus, the central portion defining the internal periphery of theannulus, the edges extending outwardly from said internal periphery; atleast one drawstring extending around at least a portion of the annulusand through the ribbon selectively to decrease the diameter of theinternal periphery of the annulus, the drawstring being disposedadjacent said center, the edges extending outwardly from the drawstring;and means securing the edges of the ribbon together, the edges of theribbon defining the external annulus periphery; the drawstring andribbon-like member being so constructed and configured that when thedraw-string is drawn the internal diameter of the annulus contracts andthe width of the annulus increases thereby substantially preventing theribbon-like member from gathering into irregular clumps as the internaldiameter of the annulus contracts.

In another facet the invention is a suture ring for use in surgery forsecuring a prosthesis in or adjacent to an annular organ structure orstabilizing or shaping a generally annular organ portion comprising, incombination: biocompatible braided fabric tube defining an annulus, oneportion of the tube defining an interior periphery of the annulus and asecond portion of the tube defining an exterior periphery of theannulus; and at least one drawstring extending around at least a portionof the annulus and through the tube selectively to decrease the diameterof the internal periphery of the annulus, the drawstring being disposedin the tube adjacent the portion of the tube that defines the interiorperiphery, the portion of the tube defining the exterior periphery ofthe annulus being free of drawstrings for being sewn to the organstructure; the drawstring and tube being so constructed and configuredthat when the draw-string is drawn the internal diameter of the annuluscontracts and the width of the annulus increases thereby substantiallypreventing the fabric of the tube from gathering into irregular clumpsas the internal diameter of the annulus contracts.

In another facet the suture ring comprises biocompatible braided fabrictube defining an annulus, one portion of the tube defining an interiorperiphery of the annulus and a second portion of the tube defining anexterior periphery of the annulus; and at least two radiopaque threadsegments lying side by side and extending around at least a portion ofthe annulus for permitting locating of the suture ring by x-radiation,the radiopaque thread being disposed in the tube intermediate theportion of the tube that defines the interior periphery and the portionof the tube defining the exterior periphery of the annulus forpermitting the tubing to be sewn through with a needle withoutinterference.

The suture ring comprises, in one embodiment, a single length of tubingcomprising braided biocompatible fibers, said tubing having first andsecond ends; one half of said tubing lying inside the other half of saidtubing thereby forming a tube one half the length of said tubing, saidtube having third and fourth ends and having an inner tubing wall and anouter tubing all; means securing the first and second ends of the tubingtogether to form an end-to-end tubing joint, the end-to-end tubing jointbeing so constructed and positioned as to comprise a portion of innertubing wall spaced from the ends of said double walled tube; meanssecuring the third and fourth ends of the tube together to form saidtube into an annulus.

In another embodiment, the suture ring comprises an annulus formed oftubing comprising braided biocompatible walls defining an inner annularperiphery and an outer annular periphery; drawstring means extendingthrough the wall of the tubing and inside the tubing around andproximate to at least a portion of the inner annular periphery of theannulus; and at least two colored marker sutures sewn into the tubingdefining respective portions of the annulus to be sutured, when used,adjacent respective portions of the annular organ structure.

In yet another embodiment the suture ring comprises an annulus formed oftubing comprising braided biocompatible walls defining an inner annularperiphery and an outer annular periphery; drawstring means comprising aplurality of drawstrings extending through the wall of the tubing, eachdrawstring extending inside the tubing around and proximate to at leasta portion of the inner annular periphery of the annulus, the respectivedrawstrings defining respective portions of the annulus to be sutured torespective portions of the annular organ structure, the drawstringsbeing so constructed and configured with respect to the annulus as topermit the user to pull and tie each pair of drawstrings independentlyof each other pair of drawstrings for contracting the annulus only inthe portion of the annulus defined by the respective drawstring. Therespective pairs of drawstrings may be colored differently from oneanother to permit visual identification of each respective pair ofdrawstrings.

The invention is also embodied in an annuloplasty ring for use inrepairing a human heart valve annulus, said ring having an inner annularperiphery and an outer annular periphery and, between said peripheries,a first face constructed and configured to lie, When in use, against theannulus defined by the tissue surrounding a human tricuspid heart valve,and a second face opposite the first face, the annuloplasty ringcomprising a flexible contractible portion, and at least one pair ofdrawstrings for contracting said contractible portion, said drawstringsexiting the first face of the ring lying against the tissue annulus.

The annuloplasty ring may have an inner annular periphery and an outerannular periphery constructed and adapted for being sutured to the humanheart tissue and, lying between said peripheries, a first faceconstructed and configured to lie, when in use, against the annulusdefined by the tissue surrounding a human tricuspid heart valve, and asecond face opposite the first face, the annuloplasty ring comprising aflexible contractible portion, and at least one pair of drawstrings forcontracting said contractible portion, said drawstrings exiting thefirst face proximate the inner annulary periphery for ring lying againstthe tissue annulus and being spaced from the outer annulary periphery.

The annuloplasty ring may be specifically for use in repairing a humanmitral heart valve having an anterior segment and a right and leftposterior segments. The ring comprises, in this embodiment, a braidedfabric tube, means connecting the ends of the tube to thereby form thetube generally into an annulus and a stiffener wire extendingsubstantially the length of the anterior segment, the stiffener wirehaving first and second ends, said ends being configured to form loopson the respective ends thereof. A first string the ends of which extendoutwardly through the tube walls at first and second points respectivelyis provided. The first and second points are spaced from the first andsecond ends of the wire. The string extends inside the tube a pointadjacent an end of the wire, at which point the string extends outwardlythrough the wall of the tube, thence around the tube, thence inwardlythrough the walls proximate the said end of the wire, thence through theloop in said end of the wire, thence outwardly through the walls, thencearoun the first string outside the tube, thence inwardly through thewalls and over the first string, forming a knot to secure said end ofthe wire to the tube and to the first string to the first end of thewire, and thence into the tube and along the tube. At the second end ofthe tube, the knot is repeated from the direction of the wire with orwithout variation, e.g. reversal, in mirror image, etc. From the secondend of the wire the string extends along the inside of the tube a seconddistance and thence outwardly through the tube wall at a second pointsaid second distance from the second end of the wire, a first end of thefirst string extending out of the tube wall proximate the first pointthe second end of the first string extending out of the wall proximatethe second point. A second string extends from outside the annul usproximate a third point, through the tube away from the first end of thewire toward the second point, outwardly through the tube wall andinwardly through the tube wall proximate a fourth point to secure thesecond string proximate said fourth point, along the inside of the tubeto proximate a fifth point, and thence through the tube wall, a firstend of the second string extending out of the tube wall proximate thethird point, the second end of the second string extending out of thetube wall proximate the fifth point. The third point may be adjacent thefirst point and the fifth point may be adjacent the second point, thesecond string form a knot at the fourth point if desired, and the firstends of the respective strings comprise a first pair of drawstrings forpermitting contraction of the annul us between the first end of the wireand the first point and between the first point and the third point,respectively and the second ends of the respective strings comprise asecond pair of drawstrings for permitting contraction of the annulusbetween the second end of the wire and the second point and between thesecond point and the third point, respectively.

One or more strings may be provided extending from outside the annulusproximate said first point, through the tube away from the first end ofthe wire toward the second point, outwardly through the tube wall andinwardly through the tube wall proximate a third point, that may, ifdesired, be approximately equidistant from the first and second ends ofthe wire, to secure the second string proximate said third point, alongthe inside of the tube to proximate the second point, and thence throughthe tube wall, a first end of the second string extending out of thetube wall proximate the first point, the second end of the second stringextending out of the tube wall proximate the second point; the firstends of the respective strings comprising a first pair of drawstringsfor permitting contraction of the annulus between the first end of thewire and the first point and between the first point and the thirdpoint, respectively; the second ends of the respective stringscomprising a second pair of drawstrings for permitting contraction ofthe annulus between the second end of the wire and the second point andbetween the second point and the third point, respectively. The seconddrawstring need not permit contraction of the entire distance betweenthe first and third and/or second and third points, respectively. If, asis clearly contemplated by the invention, a third drawstring is used thesame result is achieved with substantially the same structure in thesame way. lndeed, the drawstrings my be embodied in a series of shorterdrawstrings. It will be understood, of course, that the greatercontraction normally occurs between the first and second points lyingopposite the portion wherein the stiffener lies. Thus, while a minimumof two drawstrings are required to obtain optimum functionalperformance, any number additional drawstrings would be equivalent inthat the same contraction can be obtained in the same way, except inshorter segments of the annuloplasty ring.

The wire is preferably polished on all surfaces, the ends thereof areradius Ed and wherein the loops are formed without denting the wire inthe portions thereof that lie adjacent the ends of the wire.

More generally, the invention may be a suture ring for use in surgeryfor securing a prosthesis in or adjacent to an annular organ structureor stabilizing or shaping a generally annular organ portion comprising,in combination: an annul us formed of tubing comprising braidedbiocompatible walls defining an inner annular periphery and an outerannular periphery; drawstrings extending through the wall of the tubingand inside the tubing around and proximate to at least a portion of theinner annular periphery of the annulus; and stitching extending throughthe walls of the tube around the annulus fixing the drawstringsproximate the inner annular periphery; the annulus and drawstrings beingso constructed and configured that when the drawstrings are tied theinner annulus contracts and the distance between the inner and outerperipheries increases thereby substantially preventing gathering of thetubing.

One facet of the invention is embodied in a stiffener wire for a mitralannuloplasty ring comprising a biocompatible wire in the configurationof an arc substantially defined by a radius equal to the radius of themitral valve for which the annuloplasty ring is intended for use, thewire forming the arc having an inner periphery and an outer periphery,the respective ends of the wire being constructed to define at each enda generally circular passage through a loop substantially tangentialwith the outer periphery of the wire, the wire being smooth, free ofsharp structures or edges, and free of indentations.

As an annuloplasty ring for use in repairing a human mitral heart valvehaving an anterior segment and a right and left posterior segments, thering may have a first face constructed and configured to lie, when inuse, against the annul us defined by the tissue surrounding a humanheart valve, and a second face opposite the first face, the annuloplastyring comprising said ring having a first face constructed and configuredto lie, when in use, against the annulus defined by the tissuesurrounding a human heart valve, and a second face opposite the firstface, the annuloplasty ring comprising: a first portion constructed andconfigured to form a curved member that encompasses substantially thewhole of the anterior segment of the human valve annulus; a secondportion constructed and configured to form a flexible, contractiblemember that encompasses substantially the whole of the right and leftposterior segments of the human mitral valve annulus; and means in thering for selectively contracting, independently of one another, eitherthe right posterior segment or the left posterior segment, or bothposterior segments; the second portion being so constructed andconfigured and connected respectively at first and second ends thereofto first and second ends, respectively, of the first portion, the firstportion being relatively substantially more rigid that the secondportion, the first and second ends of the second portion being soconstructed and configured as to permit hinging movement of the secondportion relative to the first portion adjacent the ends of the firstportion to permit the ring to conform to the human mitral valve annulus.

The invention may be in the form of an annuloplasty ring for use inrepairing a human mitral heart valve having an anterior segment and aright and left posterior segments, said ring having a first faceconstructed and configured to lie, when in use, against the annulusdefined by the tissue surrounding a human heart valve, and a second faceopposite the first face, the annuloplasty ring comprising: a firstportion constructed and configured to form a curved member thatencompasses substantially the whole of the anterior segment of the humanvalve annulus; a second portion constructed and configured to form aflexible, contractible member that encompasses substantially the wholeof the right and left posterior segments of the human mitral valveannulus; the first and second portions together constructed andconfigured such that the first and second portions, respectively, liegenerally in first and second planes; and means in the ring forselectively contracting, independently of one another, the rightposterior segment proximate one end of the curved member, the rightposterior segment distal from the said one end of the curved member, theleft posterior segment proximate the other end of the curved member, orthe left posterior segment distal from the said one end of the curvedmember. The second portion may be adapted to lie adjacent the leftposterior segment is contractible by means of a first pair ofdrawstrings and the second portion that is adapted to lie adjacent theright posterior segment is contractible by means of a second pair ofdrawstrings. The drawstrings preferably exit the first face of the ringthat is constructed and configured to lie against the tissue annulus.

The annuloplasty ring of this invention is, in one form adapted for usein repairing a human mitral heart valve having an anterior segment and aright and left posterior segments, said ring having a first faceconstructed and configured to lie, when in use, against the annulusdefined by the tissue surrounding a human heart valve, and a second faceopposite the first face, the annuloplasty ring comprising: a firstportion constructed and configured to form a curved member thatencompasses substantially the whole of the anterior segment of the humanvalve annulus; and a second portion constructed and configured to form aflexible, contractible member that encompasses substantially the wholeof the right and left posterior segments of the human mitral valveannulus; and at least one pair of drawstrings in the second portion,said portion being contractible by means of said drawstrings, saiddrawstrings exiting the first face of the ring intended to lie againstthe tissue annulus.

The annuloplasty ring may, however, be adapted for use in repairing ahuman tricuspid heart valve, said ring having a first face constructedand configured to lie, when in use, against the annulus defined by thetissue surrounding a human tricuspid heart valve, and a second faceopposite the first face, the annuloplasty ring comprising a flexiblecontractible portion, an at least one pair of drawstrings forcontracting said contractible portion, said drawstrings exiting thefirst face of the ring lying against the tissue annulus.

The tricuspid annuloplasty ring embodiment may comprise an annuluscomprised of multi-layers of braided tube formed from a single length oftubular braid that is invaginated to form a double walled tube havingfirst and second ends and inner and outer walls, a roll over fold formedat one end thereof, and the two cut ends formed at the other endthereof, the two walls of the tube being heat sealed together at the cutends. In the preferred manufacture of the invention, the tubing is cutand the two out ends are sealed together in the same operation bymelting the polymer of which the tubing is formed. The tube is thenrolled so that the heat seal line lies substantially centrally in theinner wall of the tube and is then heat set into a "V" configuration toproduces an eight walled flexible contractile member.

The invention is embodied in a method of manufacturing an annuloplastyor suture ring comprising the steps of: invaginating tubing braided ofmeltable, heat setable polymer fibers to form a tube of an outer layerand an inner layer of tubing, a first end of the tube thus formed beingdefined by an annular, inward fold of the tubing from the outer layer tothe inner layer; forming a second end of the tube by melting the innerand outer layers of tubing to fuse said layers together in an annularseal between said layers; and sliding said layers relative to each otherdefined new ends of annular, inward folds of tubing and to space theannular seal distal from and between the newly formed ends inside theouter layer of the tube. The method may further comprise heat settingthe thus formed tube into a lateral V configuration having a center heatset crease comprising four layers of tubing.

More generally, the invention may be in the form of a saturable stripsuitable for use in the manufacture of prosthetic devices comprising anelongate tube formed of an outer layer and at least one inner layer ofheat set braided polymeric fabric, the ends of the saturable strip beinginward annular folds of said fabric, the tube being heat set to define aribbon the center of which is a heat set bend comprising at least fourlayers of such fabric defining a lateral cross-section of the strip intoa generally V-shaped configuration, the outer layer of fabric formingsaid strip being free of joinders of the fabric.

In a specific application, one facet of the invention is embodied in astiffener wire for use in annuloplasty rings comprising flexure fatigueresistant biocompatible corrosion resistant metal wire the centralmajority of the wire being formed into an arc, the respective ends ofthe wire forming a loop externally tangential to said arc, the ends ofthe wire lying immediately adjacent portions of the wire spaced from theends, the loops and the arcuate central majority lying in the sameplane, the ends of the wire and all surfaces of the wire being free ofsharp structures, the portions of the wire immediately adjacent the endsof the wire being free of distortion or reduction in diameter.

Other objectives and advantages of this Invention will be more apparentfrom the detailed description of the device which follows.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention may be better understood and the advantages willbecome apparent to those skilled in the art by reference to theaccompanying drawings, wherein like reference numerals refer to likeelements in the several figures, and wherein:

FIG. 1 depicts a plan view from the tissue annulus aspect of thepreferred embodiment of the ring intended for the mitral valve.

FIG. 2 depicts a plan view from the atrial aspect of the preferredembodiment of the ring intended for the mitral valve, portions depictingthe internal structure of the ring.

FIG. 3 depicts a side view of the ring intended for mitral valve repair,a hinged, bent bi-planar configuration being shown in broken lines.

FIG. 4A depicts an end view of the preferred embodiment of the ringintended for mitral valve repair.

FIG. 4B depicts an end view of the preferred embodiment of the ringintended for mitral valve repair, the rigid portion being bent at thehinge portions to lie outside the main plane of the ring.

FIG. 5 depicts a cross-sectional view taken along line 5--5 of FIG. 2.

FIG. 6 depicts a cross-sectional view taken along line 6--6 of FIG. 2.

FIG. 7 depicts a plan view from the tissue annulus aspect of thepreferred embodiment of the ring intended for the tricuspid valve.

FIG. 8 depicts a plan view from the atrial aspect of the preferredembodiment of the ring intended for the tricuspid valve, portionsdepicting internal structure.

FIG. 9 shows a cross-sectional view taken along line 9--9 of FIG. 8.

FIG. 10 is an isometric view of the preferred embodiment of the ring formitral valve repair sewn onto the mitral annulus of the heart.

FIG. 11 is a plan view of the preferred embodiment of the ring fortricuspid valve repair sewn onto a typically enlarged tricuspid annulusand insufficient tricuspid valve of the heart.

FIGS. 12A, 12B, 12C and 12D depict the stiffener wire used in the mitralvalve, FIGS. 12A and 12B depicting the stiffener wire duringmanufacture, with the end loops partially formed, FIGS. 12C and 12Ddepict the stiffener wire in a further stage of manufacture, the loopsand the wire lying in the same plane.

FIG. 13 is an exploded perspective view depicting a jig for forming thestiffener wire.

FIGS. 14A and 14B depict, respectively, a side elevational view and abottom plan view of the bending tool of FIG. 13.

FIG. 15 depicts the tie of the drawstring to the stiffener wire beforetightening the same into a knot.

FIGS. 16A, 16B,16C, 16D and 16E depict progressive steps in theformation of an invaginated braided tube used in forming the ring.

FIGS. 17A, 17B, 17C, 17D and 17E depict the tube at various stagesduring the formation of the invaginated tube used in forming the ring,FIG. 17E being a cross-sectional view of the tube as depicted in FIG.17D, the section taken along lines 17E--17E in the direction of thearrows.

FIG. 18 is an exploded perspective view of the jig fixing theinvaginated tube into a V configuration for being heat set in that Vconfiguration.

FIG. 19 is a perspective view of the heat set V-shaped invaginated tubebefore being formed into an annulus.

FIG. 20 depicts a suture ring suitable for use on prosthetic heartvalves and other prosthetic devices. While a drawstring arrangement isnot required for the suture ring, such an arrangement may be used, ifdesired, to secure the suture ring to the valve ring.

FIG. 21 depicts a cross-section of the suture ring FIG. 20.

FIG. 22 depicts an enlarged view of the interior construction of aportion of the suture ring FIG. 20 where the drawstrings exit, one-halfof the ring fabric structure being cut away to expose the interior.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The following description of the preferred embodiments of the inventionare exemplary, rather than limiting, and many variations and adaptationsare within the scope of the invention.

In one facet, the invention is directed to adjustable and flexibleatrioventricular annuloplasty rings containing circumferentialradiopaque markers with one preferred embodiment for use in mitral valveand a second preferred embodiment for use in tricuspid valve repair.Adjustment of the ring diameter is achieved by means of internaldrawstrings. To avoid the presence of a bulky knot on the inflow aspectof the rings, the drawstring exit points are preferably located on theface of the ring which lies adjacent to the tissue annulus. Hence, whenthe drawstrings are tightened and pairing ends are tied together, theknots are formed between the annulus and the ring, out of the directblood flow.

In the preferred embodiment of the invention intended for use in themitral valve, the flexible, contractile portion of the prosthesis isformed to fit about the base of the posterior leaflet of the valve. Aplurality of pairs of drawstrings are located in the posterior segmentof the ring to allow adjustment of segments of the posterior portion ofthe mitral valve annulus. A curved framework member located in theanterior portion of the prosthesis is to maintain the natural geometryof the anterior segment during implantation. It is shaped to follow acurved path on an inclined plane on the sub aortic curtain above the socalled annulus of the anterior leaflet. Colored trigone markers in theanterior segment are used as sizing and implanting guides. When themitral annuloplasty ring is secured into position about the valve, anyor all of the drawstrings located in the posterior segment of the valveannulus may be tightened if required to halt or minimize any residualvalvular insufficiency. Drawstring tightening may be made individuallyor together in pairs to minimize any remaining insufficiency. This finetuning capability allows a larger, rather than a smaller ring to beimplanted and then the size optimally reduced.

In the preferred embodiment of the invention intended for use in thetricuspid valve, the prosthesis is flexible around its circumference andis formed to fit about the base of the valve leaflets. A contractibleportion of the prosthesis is formed to fit about a substantial portionof the base of the posterior segment, and may extend into ainsubstantial portion of the base of the anterior segment of the valveannulus. This contractible segment incorporates a pair of drawstrings toallow adjustment of a substantial segment of posterior annulus and aninsubstantial segment of the anterior annulus at implantation. When thetricuspid variant is secured into position about the valve, thedrawstrings located in the posterior segment of the valve annulus may betightened if required. Tightening may be individually or in pairs tominimize any remaining insufficiency. This fine tuning capability allowsa larger, rather than a smaller ring to be implanted and then the sizeoptimally reduced.

The flexible contractible body of the ring common to both variants is ofa biocompatible cloth, preferably of a braided polyethertetraphylatetubular material. During construction of the ring, the tubular braid iscut to length and invaginated to form a double walled tube having a rollover fold at one end, and the two cut ends at the other. The two wallsof the tube are heat sealed (welded) together close to the two cut endsand at an appropriate distance from the folded end using a heated knife.This heat seal forms a circumferential weld around the tube. The tube isthen rolled so that the weld line will lie substantially centrally inthe inner wall of the tube. The tube is then heat set into a "V"configuration. This configuration produces an eight walled flexiblecontractile member when the annuloplasty ring is completed. Two of themany steps in the completion of the ring include the sewing of thefolded ends together to form a radial seam, and sewing of the pieces ofthe "V" together to form a circumferential seam. Various components,such as drawstrings, stiffener and radiopaque markers are convenientlyplaced within and/or sewn in the "V" form before the circumferentialseam is completed. This construction method produces an annuloplastyring that is relatively simple to manufacture, yet contains drawstringsto provide adjustability, radiopaque markers for postoperativeassessment, and a semi-flexible member in the anterior portion of themitral variant to maintain the natural geometry of the intratrigonal andanterior leaflet distance. At the same time it provides adequatestrength and flexibility, yet permits a low needle penetration force forconvenience of implantation. A particular advantage of this constructionis that there are no portions of the textile material that might fray,and that the weld line is so placed within the ring is bothinconspicuous and not subject to undue stresses. The body issubstantially oval in cross-section.

Referring to the drawings wherein like numerals indicate like elementsthere is shown in FIG. 1 and FIG. 2 plan views (from the annulus andatrium aspects respectively) of the preferred embodiment of a flexible,adjustable annuloplasty ring intended for the mitral valve designated as10. FIG. 3 shows a side view and FIG. 4 shows an end view of thepreferred embodiment of the variant of the ring intended for the mitralvalve. FIG. 5 shows a cross-sectional view taken along line 5--5 of FIG.2. FIG. 6 shows a cross-sectional view taken along line 6--6 of FIG. 2.

The device is composed of a tubular body of textile nature 11, which hasits folded ends sewn together at seam 12 to form a ring. The ring hasthree segments, the anterior segment 13, the right posterior segment 14,and the left posterior segment 15. In the interior of tubular body 11are provided filiform strings 20, 21, which have external portions 22,23, 24, 25. These strings, which are preferably of a braided polyestersurgical suture, emerge from the annulus face of the ring at exit points26, 27, 28, 29 respectively. The distance between exit points 26 and 28are approximately 3 mm. The distance between exit points 27 and 29 issimilar.

The strings are anchored to the ring at points 30, 31, and 32. Points 33and 34 are colored markers sewn onto the upper (atrial) surface of thering that are intended as guides for implantation. These points areintended to lie adjacent to the right and left fibrous trigones of themitral annulus. Also at implantation, point 31 will approximatelycorrespond to the junction of the anterior leaflet and the rightcommissural leaflet of the mitral annulus. Point 32 will approximatelycorrespond to the junction of the anterior leaflet and the leftcommissural leaflet. An internal curved flexible stiffener member 35spans the area corresponding to the anterior segment of the mitralannulus from points 31 to 32, and has a closed loops 36, 37 at its ends.Drawstring 20 is passed through these loops and through the walls ofbody 11 to form part of the anchor knots at 31 and 32. Drawstring 21 ispassed through the walls of body 11 to lie externally for a shortdistance 30 and is tied internally to form the anchor knot laying underexternal portion 30.

The framework or stiffener member 35 is preferably of a biocompatiblecorrosion resistant metal wire with good flexure fatigue resistance suchas Carpenter MP35N® alloy or Elgiloy®.

Reference is made briefly to FIGS. 12 through 14. A wire 35 of thematerial described, e.g. Carpenter MP35N, 0.028" diameter, orequivalent, is first inspected. Next, the wire is cut to the desiredlength, with an abrasive saw, or an equivalent device, burnished toassure that it is smooth, and secured in a jig such as is depicted inFIG. 13. The jig comprises a base plate 310, a locking bar 311 and awedge plate 312 having an incline surface 314 are secured to the baseplate. A lock plate 315 is secured to the base plate 310 lock bar 316,has a beveled corner 317 to receive the wire 35. Lock bar 316 interactswith lock bats 311-315 and locks firmly in position the wire 35. Thewire 35 extends to the edge of the base plate which serves as measure ofthe length of wire to be formed into a loop and lies adjacent a mandrelpost 318 that is less than the diameter of the loop to be formed in theend of wire 35. A bending tool 319, comprising a knob capable of beinggripped and turned, with a downwardly extending portion 320 havingformed centrally therein an aperture 321 sized to slip snugly overmandrel post 318 and an engaging post 322 that is spaced from theaperture a distance slightly larger than the diameter of the wire 35.The bending tool is fitted over the mandrel post, the wire 35 beingreceived between the mandrel post and the engaging post. The bendingtool is turned thereby bending the wire 35 into a semihelical loop. Itis necessary to bend the wire into a smaller loop than the ultimatelydesired loop because the wire rebounds slightly from its ultimatelylooped configuration. When the bending tool is removed, the wire, whichhas been burnished to assure that it is smooth, assumes theconfiguration shown in FIGS. 12A and 12B, with the loop, such as loop36a or 37a, spiraling partially out of the plane of the wire. The end ofthe wire, e.g. 36b or 37b, which has been smoother cut with an abrasivesaw and rounded and burnished to remove all sharp edges, burrs, etc., isthen bent downwardly so that the loops lie in the same plane as thewire, as shown in FIGS. 12C and 12D, the ends lying closely adjacent thewire a short distance from the ends. The loop is bent to assure that theend of the wire, as bent, depicted in FIGS. 12A and 12B, does notoverlap the portion of the wire to which is closely adjacent. When theloop is bent into the plane of the wire, the wire in that portion is notdented, distorted or deformed. As a final step, before final inspection,the stiffener 35 is burnished again to assure that it is perfectlysmooth, free of indentations or deformations that may weaken it, andfree of sharp edges or other structures that might abrade the fabric ofthe ring.

A colored demarcation suture line 38 on the upper (atrial) surface ofthe ring body indicates to the surgeon a line, outside of which theimplanting sutures must be placed to avoid interference with theinternal drawstrings or the stiffener member. A corresponding, butpreferably uncolored, demarcation suture line 39 is situated on thelower (annulus) surface of the ring body. A flexible radiopaque member40, is contained within body 11, in the posterior region betweendrawstring anchor points 31 and 32. This member, in conjunction withmetallic stiffener 35, forms a circumferential X-ray marker. Member 40may conveniently be composed of a single continuous length of 0.020"diameter extruded silicone rubber impregnated with 55% Barium Sulfateand 6% Tungsten. Material of this composition and diameter issufficiently radiopaque, but does not unduly impede the passage of theneedles of the implanting sutures. It has elements 41, 42, "hairpin"bends 43, 44, and ends 45, 46. The "hairpin" bends 43 44, lie adjacentto loops 36, 37 respectively, and ends 45, 46 lie adjacent to seam 12.

FIG. 5 shows a cross-sectional view taken along line 5--5 of FIG. 2.Cloth layers 100, 101, 102, 103, 104, 105, 106, 107 are formed from asingular tubular braided length of material folded and joined aspreviously described. The four cloth layers, when folded and heat setform an upper (atrial) surface 100, and a lower surface 107 that willlie on the natural annulus. Colored demarcation stitch 38 passes fromcloth layer 100, through layers 101, 102, 103 and hence back to layer100. The second demarcation stitch 39, which is preferably uncolored(white), is similarly passed from cloth layer 107, through layers 106,105, 104 and hence back to layer 107. Demarcation sutures 38, 39 passingthrough their respective cloth layers delineate channel 108 whichcontains drawstring 20 (or 21). Radiopaque marker member portions 41, 42are enclosed between cloth layers 103, 104. A helical, continuous,circumferential sewn seam 109 joins cloth layers 100, 101, 102, 103 tocorresponding cloth layers 107, 106, 105, 104.

FIG. 6 shows a cross-sectional view taken along line 6--6 of FIG. 2.Framework member 35 is retained along its length against the fold 110aof the cloth layer 103, 104 by a continuous helical thread 111, and/orby suture ties 38 and 39, for example. The fold 110a is a single layerof tubing lying innermost in the four-layer braided fabric construction,the exterior bend 110b forming the outermost layer of said four-layerconstruction

FIG. 7 and FIG. 8 show plan views (from the annulus and atrial aspectsrespectively) of the preferred embodiment of a flexible, adjustableannuloplasty ring intended for the tricuspid valve designated as 200.FIG. 9 shows a cross-sectional view taken along line 9--9 of FIG. 8. Thedevice is composed of a tubular body of textile nature 201, which hasits folded ends sewn together at seam 202 to form a ring. In theinterior of tubular body 201 is provided a filiform string 203 which hasexternal portions 204, 205. This string, which is preferably of abraided polyester surgical suture, emerges from the annulus face of thering at exit points 206, 207. The distance between exit points 206 and207 is approximately 3 mm. The string also emerges from, passes aroundthe body (208, 209) and reenters the body 201 at the drawstring anchorpoints. The string is anchored in the ring by internal looped knotsadjacent to external loops 208, 209.

A colored marker 210 is sewn onto the upper (atrial) surface of thering. This is a guide to the surgeon, indicating the point that shouldbe positioned adjacent to the junction of the septal and anteriorleaflet at implantation. A colored demarcation suture line 211 on theupper (atrial) surface of the ring body indicates to the surgeon a line,outside of which the implanting sutures must be placed to avoidinterference with the adjustable segments of the internal drawstring203. A corresponding, but preferably uncolored, demarcation suture line212 is situated on the lower (annulus) surface of the ring. A flexiblemember 213, is contained within body 201. This member forms acircumferential radiopaque marker. It may conveniently be composed of asingle length of 0.020" diameter extruded silicone rubber impregnatedwith 55% Barium Sulfate and 6% Tungsten. This member 213, having ends214, 215 lying adjacent to seam 202 passes twice around thecircumference of the ring to form concentric members 216, 217.

FIG. 9 shows a cross-sectional view taken along line 9--9 of FIG. 8.Cloth layers 300, 301, 302, 303, 304, 305, 306, 307 are formed from asingular tubular braided length of material folded and joined aspreviously described. The four layers, when folded and heat set, form anupper (atrial) surfaces 300, a lower surface 307 that will lie on thenatural annulus. Colored demarcation stitch 211 passes from cloth layer300, through layers 301, 302, 303 and hence back to layer 300. A seconddemarcation stitch 212, which is preferably white, is likewise passedbetween cloth layer 307, through layers 306, 305, 304 and hence back tolayer 308. Demarcation sutures 211, 212 passing through their respectivecloth layers delineate channel 308 which contains drawstring 203.Radiopaque marker member elements 216, 217 are enclosed between clothlayers 303, 304. A helical, continuous, circumferential sewn seam 309retains cloth layers 300, 301, 306, 307 together.

In the embodiment of the annuloplasty ring specifically adapted for usein repairing a human mitral heart valve having an anterior segment and aright and left posterior segments a braided fabric tube is connected toform the tube generally into an annulus. The stiffener wire extendingsubstantially the length of the anterior segment, the stiffener wirehaving first and second ends, said ends being configured to form loopson the respective ends thereof. As depicted in FIG. 15, a first string20 extends from channel 108 upwardly through the wall 110a of the tubeat a first point 20a a first distance from the first end of the wireinto the tube. Adjacent the first end of the wire the string extendsoutwardly through the tube four-layer wall at 20b thence around the tubeas indicated at 20c, thence inwardly through the four layers proximatethe first end of the wire, 20d, thence through the loop 37 in said firstend of the wire 35, thence outwardly through the walls, 20e, thencearound the first string outside the tube, 20f, thence inwardly throughthe walls, 20a, and over the first string at again, 20h forming a knotto secure the string 20 and the first end loop 37 of the wire 35 to thetube proximate the first end of the wire. The string 20 then extendsthrough the wall 110a at 20i, and along the length of the tube. At thesecond end of the tube, knot is repeated from the direction of the wire,i.e. a mirror-image of the arrangement just described is formed securingthe other end of the wire and the string to the tube proximate thesecond end of the tube. As will be apparent, the securement justdescribed can be accomplished from either direction, relative to the endof the wire, and may be the same or reversed, e.g. a mirror image knot,at the respective ends of the wire. Other knot securements may also beused. From the second end the string extends along the inside of thetube a second distance and thence outwardly through the tube wall at asecond point said second distance from the second end of the wire, afirst end of the first string extending out of the tube wall proximatethe first point, the second end of the first string extending out of thewall proximate the second point 20b. The points 20b, 20e, and 20g may becoincident, i.e. a single hole may define all of these points.

One or more strings may be provided extending from outside the annulusproximate said first point, through the tube away from the first end ofthe wire toward the second point, outwardly through the tube wall andinwardly through the tube wall proximate a third point, that may, ifdesired, be approximately equidistant from the first and second ends ofthe wire, to secure the second string proximate said third point, alongthe inside of the tube to proximate the second point, and thence throughthe tube wall, a first end of the second string extending out of thetube wall proximate the first point, the second end of the second stringextending out of the tube wall proximate the second point; the firstends of the respective strings comprising a first pair of drawstringsfor permitting contraction of the annulus between the first end of thewire and the first point and between the first point and the thirdpoint, respectively; the second ends of the respective stringscomprising a second pair of drawstrings for permitting contraction ofthe annulus between the second end of the wire and the second point andbetween the second point and the third point, respectively. The wire ispreferably polished on all surfaces, the ends thereof are radius Ed andwherein the loops are formed without denting the wire in the portionsthereof that lie adjacent the ends of the wire.

FIG. 10 shows an isometric view of the preferred embodiment of the ringfor mitral valve repair sewn onto the mitral annulus of the heart (theleft atrium is removed for clarity of illustration). The heart is shownduring ventricular systole (i.e. the mitral valve is closed and the leftventricular outflow tract is pressurized). The annuloplasty ring 10, ispositioned such that colored markers 33, 34, are coincident to the rightfibrous trig one 401 and left fibrous trig one 402 of the mitral valveapparatus. The anterior leaflet 403 is shown coapting to the posteriorleaflet 404. Seam 12 will lie approximately at the midpoint posteriorportion of the annulus. Drawstring anchor point 31 is located on theannul us approximately at the junction of the anterior leaflet and theright commissural leaflet, 405. Likewise, drawstring anchor point 32 islocated on the annul us approximately at the junction of the anteriorleaflet and the left commissural leaflet, 406.

The curved anterior portion of the ring 13 containing the internalcurved framework member spans the anterior segment of the mitral annulus403 from points 31 to 32. As manufactured, the plane of segment 13 liesin the same plane as the ring, as shown in solid lines in FIG. 3 and asdepicted in FIG. 4A. The flexible ring forms a hinge immediatelyadjacent the ends of the framework member permitting the frameworkmember to hinge or bend outside the plane of the ring up to an angle ofapproximately 85° relative to the plane of the remainder of the ring.Depending on the particular application of the ring, the framework may,during some periods of time, hinge such that the plane in which theframework lies is at an angle typically of about 45° and up to 85°relative to the plane of the remainder of the ring. In someapplications, the ring, including the framework portion, will liesubstantially in the same plane. The angle, if any, in which theframework lies is not a function of the annuloplasty ring per se butrather of configuration of the heart, or other organ, to which the ringis applied and to the method the surgeon uses for applying the ring. Acolored demarcation suture line 38 on the upper (atrial) surface of thering body indicates to the surgeon a line, outside which the implantingsutures 407 must be placed to avoid interference with the internaldrawstrings or the stiffener member. Numerous interrupted sutures 407,are used to fix annuloplasty ring to the mitral valve annulus and to thesub aortic curtain 408. External portions of the drawstrings 22, 23, 24,25 may be tightened and tied to the adjoining drawstring to constrictthe ring where required to correct or minimize valvular insufficiency.The act of drawing in either or both drawstrings 22, 24 and or 23, 25will cause the ring to contract between the drawstring anchor points 30and 31 or 30 and 32 respectively. The amount of contraction will dependupon how much each drawstring is tightened, and whether only one or alldrawstrings are tightened. By such means the circumference of theannulus may be further reduced to correct or minimize any remainingvalvular insufficiency following ring implantation. It is emphasizedthat, as to the present invention, there is no significance to theshowing or one or two or three pairs of drawstrings, as any number ofdrawstrings are contemplated by this invention.

FIG. 11 shows a plan view of the preferred embodiment of the inventionfor tricuspid valve repair sutured in place in the typically enlargedtricuspid annulus (as described by Bex J. P. and Lecompte Y. "Tricuspidvalve repair using a flexible linear reducer", J Cardiac Surg, 1:151,1986). The tricuspid valve has an anterior leaflet 501, a posteriorleaflet 502 and the septal leaflet 503. The junction of the septal andanterior leaflets is 504, the junction of the anterior and posteriorleaflets is 505, and the junction of the posterior and septal leafletsis marked 506. The dotted line 507 shows the circumference of theannulus before pathologic dilatation.

The annuloplasty ring 200, is positioned such that colored marked 210 isapproximately coincident with junction 504. Numerous interrupted sutures508, are used to fix annuloplasty ring to the tricuspid valve annulus.The adjustable segment is delineated from drawstrings anchor points 208to 209. Typically, this adjustable segment will approximately straddle asubstantial portion of the posterior leaflet 502, as well as thejunction of the posterior and anterior leaflets 505. It may alsostraddle an insubstantial portion of the anterior leaflet 501. The actof drawing in either or both drawstrings 204, 205 will cause the ring tocontract between the drawstring anchor points 208 and 209. The amount ofcontraction will depend upon how much the drawstring is tightened, andwhether only one or both drawstrings are tightened. By such means theenlarged circumference of the annulus may be reduced to that shown bydotted line 507. Following appropriate reduction the drawstring pairsare tied using a surgeon's knot which will lie between the ring and theannulus, out of the bloodstream.

Referring now to FIGS. 16A-16E, the initial steps in manufacturing thebraided ring is described. A pre-washed length of heat-setable, meltablebraided fiber tubing 350, e.g. Atkins & Pearce braided polyester tape,is cut to the desired length, e.g. 250-290 mm, and the cut length isslid over a mandrel, rolled back onto a pusher rod 352 so as to form adouble walled tube, having an inner wall 356 and an outer wall 354,approximately half the length of the original tubing. The tube has aninward fold 358 from outer wall 354 to inner wall 356 forming one end,the right end as depicted in FIG. 16A, the other ends of the tubing 360and 362 lying generally adjacent each other.

Referring to FIG. 16B, the double walled tube 370 is cut to a desiredlength, e.g. 112-133 mm, at 364 with a heated blade that cuts by meltingthe fibers and fusing the fibers together to form a fused end, the innerand outer walls being joined in an annular fused joint at 364.

Referring to FIG. 16C, temporary sutures 366 and 368 are secured onlythrough the outer layer 354 a desired distance, e.g., 56-66 mm from theend of the tube. The fused joint 364 is then rolled into the inside ofthe tube so as to turn a portion of the tube inside out, the temporarysutures being used to pull the layer through which they extend to rollthe tube inside out to position the fused joint in the inside wall,preferably in the center of the inside wall of the tube 370. To clarify,the tube as shown in FIG. 16B, is rolled inside out so that thesealed-cut ends are on the right as shown in FIG. 16C, the sutures areattached, and the tube is further rolled partially inside out until thesutures are at the right end as shown in FIG. 16D with the heat-sealedjoint between the original ends of the tubing inside the final two-laytube as shown in FIG. 16.

The steps in forming the final tube are depicted in FIGS. 17A-17B anddepict the steps of one facet of the invention, namely the method ofmanufacturing an annuloplasty or suture ring comprising the steps ofinvaginating tubing 350 braided of meltable, heat setable polymer fibersto form a tube 370 of an outer layer and an inner layer of tubing, afirst end of the tube thus formed being defined by an annular, inwardfold 358 of the tubing from the outer layer to the inner layer; forminga second end 364 of the tube by melting the inner and outer layers oftubing to fuse said layers together in an annular seal between saidlayers; and sliding said layers relative to each other defined new endsof annular, inward folds of tubing and to space the annular seal 364distal from and between the newly formed ends inside the outer layer ofthe tube.

This double wall tube may be used in the devices of this invention, as asuture ring for heart valves and in any other device or method wherein afabric suture strip, ribbon or ring is used to secure a prosthesis totissue or to secure tissue to tissue.

Referring to FIGS. 18 and 19, the method, as used in making theaforementioned suture or annuloplasty rings, further comprises heatsetting the thus formed tube 370 into a lateral V-shaped band 380 havinga center heat set crease comprising four layers of tubing.

Reference is made specifically to FIG. 18 which depicts, in explodedview, the fixture for heat setting the tubing 370 into a V-shaped band380. The double walled tube 370 is slipped over a V-shaped mandrel 372which may be of metal or high temperature resistant polymer, e.g.polytetrafluoroethylene. The mandrel 370 carrying on it the tube 372 isclamped between forming tools 374 and 376 which define a V-shapedopening the size and shape of the desired V-shaped band. A pair ofbolts, C-clamps, or any other clamping device may be used to secure theforming tools together. Bolt are preferred to maintain alignment of thetools. The clamped tools with the mandrel and tube are placed in anoven, or otherwise heated, to a temperature sufficient to heat set thepolymer of which the tubing is formed without fusing it. In the case ofpolyester, temperatures in the range of 100°-110° C. are quite suitablein most instances. After a sufficient period, usually about ten minutes,to heat form the tubing, the clamped mandrel, with the tube in place, isfirst cooled to set the tube into a V-shaped band or tape 380 and thenremoved.

The V-shaped band may be secured end-to-end to define a suture ring,such as, for example, the suture ring 382 depicted FIGS. 20-22. Thesuture ring 382 is formed of a length of V-shaped band or ribbon 380secured end-to-end in any desired manner. Such a ring may be used forheart valve prostheses, for example. If desired, a drawstring 384 mayextend through the tube, and through the tube walls, around the innerperiphery of the suture ring. Pairs of demarcation seams 386 and 388 aresewn around the ring to maintain the drawstring in place and stabilizethe ring. These demarcation seams may be of different colors therebyidentifying the respective sides of the ring. The ring is closed at afirst outer periphery by closure suture 390. In use, the drawstring maybe a heat-shrink type monofilament or polyfilament string. The ring isplaced on the prosthesis, the drawstring 384 tightened and tied. Theprosthesis may then be heated causing the drawstring to form anextraordinarily tight and strong securement of the ring to theprosthesis. The use of a heat shrink drawstring is not necessary, ofcourse. In some applications, where x-ray identification or location ofthe suture ring is desirable, a radiopaque fiber 392 wrapped two or moretimes around the ring or placed such that two or more fibers lieadjacent each other.

The invention, as described, may be in the form of a suture ring for usein surgery for securing a prosthesis in or adjacent to an annular organstructure or stabilizing or shaping a generally annular organ portion.The suture ring comprises an elongate braided biocompatible ribbon 380having ends, elongate edges and a central portion, the lateralcross-section of the ribbon generally defining a V-shape, the edgesextending outwardly from the center, means securing the respective endsof the ribbon together thereby configuring the ribbon generally into anannulus, the central portion defining the internal periphery of theannulus, the edges extending outwardly from said internal periphery. Thering may be provided with at least one drawstring 384 extending aroundat least a portion of the annulus and through the ribbon selectively todecrease the diameter of the internal periphery of the annulus, thedrawstring being disposed adjacent said center, the edges extendingoutwardly from the drawstring. The drawstring may be omitted and thering secured to a valve using one or more wraps of heat-shrinkablematerial, e.g. polyester, to tie the ring to the valve. Means areprovided for securing the edges of the ribbon together, the edges of theribbon defining the external annulus periphery. The drawstring andribbon-like like member are so constructed and configured that when thedraw-string is drawn the internal diameter of the annulus contracts andthe width of the annulus increases thereby substantially preventing theribbon-like member from gathering into irregular clumps as the internaldiameter of the annulus contracts.

The ability of the ring to contract in its interior annulus withoutbunching, gathering or folding is a great advantage. The constructiondescribed permits the excess material to expand laterally outwardly asnecessary without bunching.

The method of use of is as follows. The left atrium is exposed followinga mid-line sternotomy, and cardio-pulmonary bypass established usingconventional techniques. A left ventricular drain may be inserted intothe apex of the left ventricle. The aorta is cross-clamped and a coldcardioplegia solution is pumped into the aortic root causing the heartto be cooled and inducing cardiac arrest. Alternatively, retrogradecardioplegia may be given via the coronary sinus. An incision is madeinto the left atrium, exposing the damaged mitral valve. The techniqueso far described is a general description of mitral valve exposure, andis not specific to the particular device.

Surgical techniques of implantation vary between centers. The surgeonwill then carefully examine the mitral valve mechanism to ascertain ifthe valve is amenable to repair, and if so, what the mechanism of repairwill be. For example, the lesion may be at the level of the annulus,leaflets, chordae, or papillary muscles. The appropriate surgical repairprocedure will depend upon the pathology found. In cases where theannulus is enlarged, or where a segment has been removed from the mitralvalve leaflets, the mitral valve annuloplasty ring will be implanted aspart of the repair procedure. First the appropriate size ring is chosenusing the sizer set supplied for this purpose. Interrupted sutures areplaced at the fibrous trigones, between the trigones, and around theremaining circumference of the annulus. The sutures are passed throughcorresponding portions of the annuloplasty ring, outside the line ofdemarcation, marked by the colored suture line on the atrial side of theannuloplasty ring. The ring is then pushed down the sutures until itlies on the annulus. Each interrupted suture is tied and cut. Mitralvalve competency is then assessed by suitable means (e.g. by theinjection of a saline solution through the left ventricular drain, or byremoving the aortic cross-clamp and temporarily rendering the aorticvalve incompetent). If the mitral valve is regurgitant the areas ofreflux are noted. If leakage occurs in the right posterior leaflet, thisarea of the ring is contracted by gently pulling on one or both of thedrawstrings in this region of the ring. It may be necessary to tightenone or both drawstrings pairs depending upon the individual valvepathology. Mitral valve competence is again assessed, and if necessaryfurther adjustments made.

When the surgeon is satisfied that an optimum mitral valve competencehas been achieved without compromising mitral valve opening area thedrawstrings are tied as pairs. The surplus portions of the drawstringsare cut close to the knots. Mitral valve competence is then confirmed.At this stage, should any slight reflux be present, it can be eliminatedor minimized by placing one or more plicating sutures at the appropriateportion of the annuloplasty ring. However, should a drawstring have beeninadvertently over-tightened, it may be cut below the knot to releasethe constricting segment. That portion of the ring might then need to beshortened by the placement of sufficient plicating sutures. The leftatrium is then closed, air removed from the heart, warm blood allowed toreperfuse the coronary tree, the heart defibrillated if necessary, andthe patient slowly weaned from cardiopulmonary bypass. Implantation ofthe tricuspid ring follows a similar course with variations appropriateto the different anatomy and the corresponding differences in thetricuspid and mitral annuloplasty rings.

    ______________________________________                                        References Cited                                                              UNITED STATES PATENTS                                                         ______________________________________                                        3,491,376    01/1970     Shiley                                               3,534,411    10/1970     Shiley                                               3,656,185     4/1972     Carpentier                                           4,042,979     8/1977     Angell                                               4,055,861    11/1977     Carpentier et al.                                    4,164,046     8/1979     Cooley                                               4,217,665     8/1980     Bex et al.                                           4,263,680    04/1981     Muller, et al.                                       4,290,151     9/1981     Massana                                              4,339,831     7/1982     Johnson                                              4,451,936    06/1984     Carpentier, et al.                                   4,606,911     7/1986     Ahmadi et al.                                        4,702,250    10,1987     Levy, et al.                                         4,477,930    10/1984     Totten, et al.                                       4,865,600    09/1989     Carpentier, et al.                                   4,888,009    12/1989     Lederman, et al.                                     4,917,698     4/1990     Carpentier et al.                                    5,104,406    04/1992     Curcio, et al.                                       5,104,407    04/1992     Lam et al.                                           ______________________________________                                    

PUBLICATIONS

Tsakiris AG. "The physiology of the mitral valve annulus". in The mitralvalve--a pluridisciplinary approach. ed Kalmanson D. Publishing SciencesGroup, Action, Ma., pg 21, 1976.

Getter M., Kronzon I., Slater J. et al. "Long-term follow-up aftermitral valve reconstruction: incidence of postoperative left ventricularoutflow obstruction". Circulation, 74:I-99, 1986.

Carpentier A., Deloche A., Hanania G., et al. Surgical management ofacquired tricuspid valve disease. J. Thorac Cardiovasc Surg, 67:53,1974.

Duran C. D., and Ubago J. L. M. "Clinical and Hemodynamic Performance ofa Totally Flexible Prosthetic Ring for Atrioventricular ValveReconstruction" Annals of Thoracic Surgery, 22:458, 1976.

Levine, R. A., Triulzi, M. O., Harrigan P., and Weyman, A. E. "Therelationship of mitral annular shape to the diagnosis of mitral valveprolapse", Circulation, 75:756, 1987.

Bex J. P. and Lecompte Y. "Tricuspid valve repair using a flexiblelinear reducer", J Cardiac Surg, 1:151, 1986.

What is claimed is:
 1. An annuloplasty ring comprising an annulus shaped and sized for insertion in a human heart comprised of multi-layers of braided tube. wherein each layer forms a wall, said annulus formed from a single length of tubular braid that is invaginated to form a double walled tube having first and second ends and inner and outer walls, a roll over fold formed at one end thereof, and two cut ends formed at the other end thereof, said inner and outer walls of the tube being sealed together at said two cut ends forming a seal line, said tube being rolled so that said seal line lies substantially centrally in the inner wall of the tube, said tube set to form a "V" cross-section configuration to form an eight walled flexible contractile member.
 2. The ring of claim 1, wherein said seal line is a heat seal line.
 3. The ring of claim 2 tube being heat set to form "V" cross-section configuration to form an eight walled flexible contractile member.
 4. The ring of claim 1 tube being heat set to form a "V" cross-section configuration to form an eight walled flexible contractile member.
 5. The ring of claim 4 constructed and configured to be a tricuspid annuloplasty ring.
 6. The ring of claim 1 ring having an inner annular periphery and an outer annular periphery constructed and adapted for being sutured to the human heart tissue and, lying between said peripheries, a first face constructed and configured to lie, when in use, against the annulus defined by the tissue surrounding a human heart valve, and a second face opposite the first face, said ring comprising at least one pair of drawstrings exiting the first face approximate the inner annular periphery for ring lying against the tissue annulus and being spaced from the outer annular periphery.
 7. The ring of claim 1 wherein the annulus comprises an anterior segment and a right and left posterior segments further comprises:a stiffener wire extending substantially throughout the anterior segment, the stiffener wire having first and second ends, said ends being configured to form loops on the respective ends thereof; a first string having ends which extend outwardly through the tube walls at first and second points respectively, the first and second points being spaced, respectively, from the first and second ends of the wire, extending inside the tube a point adjacent an end of the wire, at which point the string extends outwardly through the wall of the tube, thence around the tube, thence inwardly through the walls proximate the said end of the wire, thence through the loop in said end of the wire, thence outwardly through the walls, thence around the first string outside the tube, thence inwardly through the walls and over the first string, forming a knot to secure said end of the wire to the tube and to the first string to the first end of the wire, and thence into the tube and along the tube; and a second string extending from outside the annulus proximate a third point, through the tube away from the first end of the wire toward the second point, outwardly through the tube wall and inwardly through the tube wall proximate a fourth point to secure the second string approximate said fourth point, along the inside of the tube to proximate a fifth point, and thence through the tube wall, a first end of the second string extending out of the tube wall proximate the third point, the second end of the second string extending out of the tube wall proximate the fifth point.
 8. The ring of claim 7 wherein the third point is adjacent the first point and the fifth point is adjacent the second point, wherein the second string form a knot at the fourth point, and wherein the first ends of the respective strings comprise a first pair of drawstrings for permitting contraction of the annulus between the first end of the wire and the first point and between the first point and the third point, respectively and the second ends of the respective strings comprise a second pair of drawstrings for permitting contraction of the annulus between the second end of the wire and the second point and between the second point and the third point, respectively.
 9. The ring of claim 7 wherein the wire is polished on all surfaces, the second ends thereof are radiused and wherein the loops are formed without denting the wire in the portions thereof that lie adjacent the ends of the wire.
 10. The ring of claim 7 further comprising a second knot formed by the string proximate the second end of the wire, said second knot being a mirror image of the first knot.
 11. The ring of claim 1 wherein the annulus comprises an anterior segment and right and left posterior segments, and having a first face constructed and configured to lie, when in use, against the annulus defined by the tissue surrounding a human heart valve, and a second face opposite the first face, a first portion constructed and configured to form a curved member that encompasses substantially the whole of the anterior segment of the human valve annulus, a second portion constructed and configured to form a flexible, contractible member that encompasses substantially the whole of the right and left posterior segments of the human mitral valve annulus and means in the ring for selectively contracting, independently of one another, either the right posterior segment or the left posterior segment, or both posterior segments and a second portion being so constructed and configured and connected respectively at first and second ends thereof to first and second ends, respectively, of the first portion, the first portion being relatively substantially more rigid that the second portion, the first and second ends of the second portion being so constructed and configured as to permit hinging movement of the second portion relative to the first portion adjacent the ends of the first portion to permit the ring to conform to the human mitral valve annulus.
 12. The annuloplasty ring of claim 1 wherein the annulus comprises an anterior segment and a right and left posterior segments, said ring having a first face constructed and configured to lie, when in use, against the annulus defined by the tissue surrounding a human heart valve, and a second face opposite the first face, and further comprising:a first portion constructed and configured to form a curved member that encompasses substantially the whole of the anterior segment of the human valve annulus; a second portion constructed and configured to form a flexible, contractible member that encompasses substantially the whole of the right and left posterior segments of the human mitral valve annulus; the first and second portions together constructed and configured such that the first and second portions, respectively, lie generally in first and second planes; and means in the ring for selectively contracting, independently of one another, the right posterior segment proximate one end of the curved member, the right posterior segment distal front the said one end of the curved member, the left posterior segment proximate the other end of the curved member, or the left posterior segment distal from the said one end of the curved member.
 13. The mitral annuloplasty ring of claims 12 wherein the second portion that is adapted to lie adjacent the left posterior segment is contractible by means of a first pair of drawstrings and the second portion that is adapted to lie adjacent the right posterior segment is contractible by means of a second pair of drawstrings.
 14. The annuloplasty ring of claim 12 wherein drawstrings exit the first face of the ring that is constructed and configured to lie against the tissue annulus.
 15. The annuloplasty ring of claim 1 wherein the annulus comprises an anterior segment and a right and left posterior segments, said ring having a first face constructed and configured to lie, when in use, against the annulus defined by the tissue surrounding a human heart valve, and a second face opposite the first face, and further comprising:a first portion constructed and configured to form a curved member that encompasses substantially the whole of the anterior segment of the human valve annulus; and a second portion constructed and configured to form a flexible, contractible member that encompasses substantially the whole of the right and left posterior segments of the human mitral valve annulus, and at least one pair of drawstrings in the second portion, said portion being contractible by means of said drawstrings, said drawstrings exiting the first face of the ring intended to lie against the tissue annulus. 